我如何在Grails中使用Oracle创建文件上传？ [英] how do I create a file upload in grails which works with oracle?

问题描述

遇到以下问题：

我试图在grails中创建一个simpel文件上传功能。我刚刚创建了一个带有

  byte [] rawFile 
  

作为属性。 Grails为我做了大部分休息。它在dev环境中的标准hsqldb中运行良好。

然后，我将它部署到配置了oracle db（瘦驱动程序）的服务器上。除了文件上传以外，其他所有的东西都可以很好的与oracle db配合使用对于文件上传，我得到了一个（据我记忆）

SQLException：ORA-01461：只能绑定一个LONG值插入到LONG中

我尝试了几种方法修复它（包括一些到blob的列映射并使用java.sql.blob而不是字节[]），但没有真正的工作，我走了一个方向，我的代码不会再独立于数据库了。

Google并没有真正帮助我和我的grails书籍

将文件保存到磁盘并不是一个好的解决方案，我认为。

所以，这里是我的问题：

我如何在Grails中创建一个与oracle一起工作的文件上传？

更新：获得了一些其他信息。用Oracle的XE版本管理重现问题：

Hibernate为rawFile创建一个VARBINARY（255）列。所以我试图上传一个4字节的文件，它工作。

然后我手动将列的类型更改为blob，并使用更大的文件。

p>

然后我添加了

  static mapping = {
 columns { 
 rawFile类型：'blob'
} 
} 
  

我的域类，它停止工作：

lockquote
ERROR errors.GrailsExceptionResolver - [B不能转换为java.sql.Blob
java.lang.ClassCastException：[B不能转换为java.sql.Blob

： - （

解决方案

不是将类型设置为blob，而是尝试增加maxSize约束：

  static constraints = {
 rawFile（maxSize：20 * 1024 * 1024）// 20 MB 
 // ... 
} 
  

got the following problem:

I tried to create a simpel file upload functionality in grails. I just created a domain class with a

byte[] rawFile

as property. Grails did most of the rest for me. It worked fine for the standard hsqldb in the dev environment.

Then I deployed it to the server with an oracle db configured (thin driver). Everything but the file upload works fine with the oracle db. For the file upload I get a (as far as I can remember)

SQLException: ORA-01461: can bind a LONG value only for insert into a LONG

I tried several ways to fix it (including some columnmappings to blobs and using java.sql.blob instead of byte[]) but nothing really worked and I went in a direction where my code wouldn't be db independent anymore.

Google didn't really help me and my grails books don't help too.

Saving the file to the disk isn't a good solution im my opinion.

So here's my question:

how do I create a file upload in grails which works with oracle?

Update: got some additional infos. Managed to reproduce the problem with the XE-Edition of Oracle:

Hibernate creates a VARBINARY(255) column for the rawFile. So I tried to upload a 4 bytes file and it worked.

I then changed the type of the column manually to 'blob' and it worked with bigger files.

I then added

static mapping = {
    columns {
        rawFile type:'blob'
    }
}

to my domain class and it stopped working:

ERROR errors.GrailsExceptionResolver - [B cannot be cast to java.sql.Blob java.lang.ClassCastException: [B cannot be cast to java.sql.Blob

:-(

解决方案

Instead of setting the type to blob try to increase the maxSize constraint:

static constraints = {
    rawFile(maxSize: 20 * 1024 * 1024) // 20 MBs
    // ...
}

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